The proposed collaborative community-driven study is motivated by the concern of the Cincinnati school community including administrators, teachers, public health officials and nurses, parents, and others childhood exposure to traffic-related particles at schools. Traffic-related particles have been shown to exacerbate existing asthma in school-age children. It is unknown, however, the concentrations of these pollutants at schools compared to community background levels. Furthermore, anti-idling campaigns have been conducted with limited success and without measures of environmental or health impact. In order to address the community's concerns and the lack of quantitative data, a new partnership has been formed between environmental health researchers at the University of Cincinnati and community-based organizations including the Cincinnati Public Schools and the Cincinnati Health Department. This partnership will build upon the strengths of each organization to collaboratively accomplish three specific aims: 1) determine if children are exposed to increased levels of traffic-related PM at school compared to ambient levels in the communities where the children reside, 2) develop and implement a community-driven anti-idling campaign aimed at reducing children's exposure to traffic-related air pollution during school hours, and 3) evaluate the effectiveness of the research partnership and anti-idling campaign by assessing the reduction of exposure in schools and the impact on the health of children with asthma who attend these schools. The results of this reciprocal research relationship will guide future public health actions in the Cincinnati community and elsewhere, provide training and education for public health nurses, provide children with asthma and their families with objective health data, engage bus drivers in order to reduce idling, and provide a foundation for future collaborative efforts between University of Cincinnati researchers and community partners. PUBLIC HEALTH RELEVANCE: This collaborative community-driven study is motivated by the concern of the Cincinnati school community including administrators, teachers, public health officials, school nurses, and parents regarding childhood exposure to traffic-related particles at school. This partnership between the University of Cincinnati, Cincinnati Health Department, and the Cincinnati Public Schools will build upon the strengths of each organization to collaboratively determine if children are exposed to increased levels of traffic-related PM at school compared to ambient levels in the communities where the children reside. In addition, a community-driven anti-idling campaign will be developed and implemented with the goal of reducing children's exposure to traffic-related air pollution during school hours. Finally, the effectiveness of the research partnership and anti-idling campaign will be evaluated by assessing the reduction of exposure at schools and the impact on the health of children with asthma.